Chemical, food and beverage processing industries use a variety of process, transportation, and storage vessels which must be periodically cleaned. Typically, such vessels or tanks are cleaned by a controlled spraying apparatus which uses the cleaning fluid to be sprayed within the tank to drive the nozzle spray assembly of the spraying apparatus in a predetermined pattern. These devices include a primary drive shaft which is typically driven by a turbine powered by the fluid flowing through the device. The primary drive shaft is connected to a gear train which is located in a separate compartment which is sealed from the remaining portion of the device. A lubricating fluid, such as oil, is typically placed in the separate compartment for lubricating the gear train for proper operation thereof. Appropriate seals are required for the shaft extending into the secondary chamber and for sealing the chamber from the environment. However, due to the high rotational speed of the primary drive shaft and normal wear, the seals tend to wear which results in lubricating oil leaking into the vessel and thereby contaminating the vessel. This potential leakage is a very serious problem in certain type vessels, thereby making it extremely important to minimize or prevent the leakage of such lubricating fluids into the vessel. Additionally, in many installations, the spraying apparatus is permanently or semi-permanently installed within the tank. In many of these type installations, it is extremely difficult to maintain or repair such devices. Thus, in many instances these devices are allowed to go into a state of disrepair before maintenance.
There also exist devices in the prior art which use some of the cleaning solution supplied to the device as a lubricant for the gear train. However, due to its construction, wear and durability have been a serious problem due to its vulnerability to the cleaning solution. This is particularly so because in many installations the cleaning fluid is recirculated.
Applicants have invented an improved tank cleaning device which uses part of the cleaning fluid supplied to the device as the fluid to lubricate the gear train which is designed to minimize the corrosive effects of the cleaning fluid so as to provide longer wear.